1. Field of the Invention
The present invention relates to pin-type synchronizer assemblies and synchronizer pin assemblies therefor. In particular, the present invention relates to double-acting pin-type synchronizer assemblies utilizing synchronizer pin assemblies having a large diameter portion, a small diameter and an intermediate diameter portion interposed between the large and small diameter portions, the large diameter portion interacting with apertures in a sliding clutch plate to define baulking means and being axially movable relative to and resiliently biased away from the synchronizer ring associated therewith.
2. Description of the Prior Art
Change-gear transmissions utilizing double-acting pin-type synchronizers and the pin-type synchronizer assemblies therefor, including boosted-type synchronizer assemblies, are known in the prior art, as may be seen by reference to U.S. Pat. Nos. 3,739,890; 4,944,197; 4,989,706; 5,078,244; 5,078,245; 5,086,897; 5,103,952; 5,092,439; 5,111,922; 5,161,423; 5,231,895 and 5,370,013, the disclosures of which are incorporated herein by reference.
While such synchronizer assemblies and the transmissions utilizing same are well received and have had remarkable commercial success, the synchronizer assemblies may be subject to improvement by providing an assembly which eliminates the use of cantilevered pins and/or separate spring pins, spring-biased plungers and/or other pre-energizing devices.
British Patent No. 1,210,808 discloses a double-acting pin-type synchronizer assembly utilizing synchronizer pin assemblies having a large diameter baulking portion and a small diameter portion, the large diameter portion being axially movable and resiliently biased away from its associated synchronizer ring. While eliminating the need for separate pre-energizing means, the disclosed device does not prevent crash shifts if after initiating engagement of a target ratio, the operator attempted to reengage a previously engaged ratio.